Apr 16, 2025
From eggs to open sea
Fish migration and the destruction of mangroves: a silent threat to the ocean
Fish migration is one of the most fascinating and crucial phenomena for the balance of aquatic ecosystems. Many species, such as salmon and eels, undertake extraordinary journeys between seas, rivers, and brackish waters, adapting to different salinity levels and finding refuge in transitional zones. However, this dance of life is increasingly threatened by human impact.
The life of many fish begins in brackish nurseries—transitional environments like estuaries, lagoons, and mangrove forests, which are essential for the growth of fry. These ecosystems provide protection and nourishment during their earliest life stages. Many species rely on these habitats to complete their life cycles, such as:
- Salmon, which are born in freshwater, migrate to the sea, and return to reproduce.
- Eels, which follow the opposite path, spawning in the ocean and maturing in rivers.
- Tropical species (such as “Lutjanids” or “Carangids”)) that depend on mangroves for reproduction.
Without these brackish zones, the survival of many species is at risk, with severe consequences for marine biodiversity and sustainable fishing.
Mangrove forests are among the richest and most productive ecosystems on Earth: they protect coastlines, absorb CO₂, and host hundreds of marine species. Yet, they are often cleared to make way for intensive shrimp farming.
- In Indonesia, over 50% of mangrove deforestation is linked to shrimp aquaculture.
- In Ecuador, 70% of mangroves have disappeared due to tropical shrimp production.
- Globally, more than 35% of mangroves have been lost in just a few decades.
These farms cause pollution, soil degradation, and have a limited lifespan—many are abandoned after just a few years, leaving behind devastated ecosystems.
Mangrove deforestation has environmental, economic, and social consequences:
- Habitat loss: Mangroves are vital for the reproduction of many marine species. Without them, fish cannot complete their life cycles.
- Ecosystem damage: Their destruction weakens coastal health and reduces marine biodiversity, harming local communities.
- Unsustainable aquaculture: Pesticides and antibiotics pollute waters, making farms short-lived and often abandoned.
Solutions require actionable choices and practices:
-Protecting and restoring mangroves
-Promoting sustainable aquaculture that respects coastal ecosystems rather than destroying them.
-Encouraging responsible consumer and policy decisions, such as choosing certified shrimp or avoiding year-round fishing that disregards reproductive seasons.
Fish migration and the birth of new generations are a masterpiece of nature, connecting oceans, rivers, and brackish waters in a delicate balance. Destroying mangroves for shrimp production not only threatens this harmony but also jeopardizes the future of the ocean itself.
Protecting these ecosystems is not just an environmental issue—it’s a necessity for coastal communities, marine biodiversity, and the survival of fish populations, which play a fundamental role in both ecological balance and the fishing industry.